The present invention relates to an IC-card module which is a component of an IC-card for use as an identification card or the like. It also relates to an IC-card having such a module and a method of making an IC-card module.
An IC-card having an IC memory is known as a card having an information storage function. Recently, a non-contact type IC-card has been in practical use as a prepaid card for use of ski lifts or the like. Such an IC-card includes an IC chip incorporated in a card member made of a synthetic resin. More specifically, the IC-card comprises an IC-card module which is incorporated in a card member made of a synthetic resin and having a predetermined thickness, and the IC-card module comprises an electronic circuit including an IC memory and an antenna coil. The IC-card module may include a small battery as a power source or a capacitor for storing electric power supplied via the antenna coil in a non-contact manner.
When the antenna coil in the IC-card receives radio waves transmitted from a predetermined transmitter/receiver, it generates an electromotive force due to electromagnetic induction. The electromotive force is utilized to wirelessly transmit signals representative of the remaining number of times of ski lifts from the antenna coil to the transmitter/receiver. When the transmitter/receiver responds by wirelessly sending a signal for reducing the remaining number of times by one, the data in the IC memory are renewed in response to the signal.
Thus, an IC-card is suitable for use as a non-contact type information storage card. Further, the information storage capacity of an IC-card can be easily increased, and a counterfeit of the card can be effectively prevented. Accordingly, there is a demand for development of an IC-card as a portable information carrier having a high information processing ability and communicating ability.
Moreover, there is also an increasing demand for thickness reduction of an IC-card. Therefore, there is a higher possibility of deforming the IC-card when it is handled by a user. Since the IC-card incorporates an IC chip, a significant stress is likely to be applied to the IC chip when subjected to deformation. Such a situation poses problems such as detachment of the IC chip from the wiring pattern or damage to the IC chip itself. In particular, damage to the IC chip itself may cause an inconvenience that the data stored in the IC chip are lost and become difficult to recover.
It is an object of the present invention to provide an IC-card module and an IC-card which are capable of solving or lessening the above problems.
Another object of the present invention is to provide a method of making an IC-card module.
In accordance with a first aspect of the present invention, there is provided an IC-card module comprising a substrate, and an IC chip mounted on the substrate, wherein a protective member is bonded to the substrate to cover the IC chip, and wherein a clearance is provided between the protective member and the IC chip for avoiding direct contact of the protective member with the IC chip.
Preferably, the substrate may comprise a flexible synthetic resin film as a base material.
Preferably, the substrate may be provided with an antenna coil for radio communication of electrical signals processed by the IC chip.
Preferably, the protective member may comprise a protective cap in the form of a plate or a sheet formed with a recess on a surface thereof opposed to the substrate for housing the IC chip.
Preferably, the protective cap may be formed by molding a resin.
Preferably, the protective cap may comprise a first sheet member having a through-hole, and a second sheet member separate from the first sheet member, the second sheet being laminated and bonded to the first sheet member, an opening of the through-hole being closed by the second sheet member to provide the recess.
Preferably, the protective member may comprise a resin-package enclosing the IC chip with a clearance formed between the resin-package and the IC chip.
Preferably, the protective member may cover opposite surfaces of the substrate at a portion thereof on which the IC chip is mounted, a clearance being formed between each surface of the substrate and the protective member.
Preferably, the clearance between the protective member and the IC chip may be loaded with a filler having a modulus of elasticity lower than that of the protective member.
Preferably, the filler may comprise a material such as polyvinyl acetate resin emulsion adhesive which is curable at room temperature.
Preferably, the clearance between the protective member and the IC chip may be held in an oxygen-free atmosphere.
Preferably, the clearance may be filled with an inert gas.
Preferably, the IC-card module may further comprise a reinforcing member which is harder than the protective member for reinforcing the protective member around the IC chip.
Preferably, the protective member may be formed of a metal or a ceramic material.
In accordance with a second aspect of the present invention, there is provided an IC-card comprising an IC-card module which includes: a substrate, an IC chip mounted on the substrate, and a protective member bonded to the substrate to cover the IC chip, a clearance being provided between the protective member and the IC chip for avoiding direct contact of the protective member with the IC chip; wherein the IC-card module is incorporated in a card member.
Preferably, the card member may comprise a card body having a receiving portion in the form of a recess or a through-hole for housing the IC-card module, and at least one cover sheet bonded to the card body to close an opening of the receiving portion.
In accordance with a third aspect of the present invention, there is provided a method of making an IC-card module comprising: a first step of covering an IC chip mounted on a substrate with a covering material, and a second step of packaging the IC chip in a resin package over the covering material, wherein the second step includes liquefying or gasifying the covering material for penetration into the resin-package before the resin-package is cured so that a clearance is formed between the resin package and the IC chip.
Preferably, the first step may include covering, with the covering material, opposite surfaces of the substrate at a portion thereof on which the IC chip is mounted, the second step including resin-packaging the opposite surfaces of the substrate at the chip mounting portion so that a clearance is defined between each surface of the substrate and the resin package.
Preferably, the substrate may have a though-hole formed in advance, and the first step includes supplying the covering material in a fluid state to an obverse surface of the substrate and causing the covering material to flow through the through-hole to a reverse surface of the substrate so that the covering material is applied to both of the opposite surfaces of the substrate at the chip mounting portion.
In accordance with a fourth aspect of the present invention there is provided an IC-card module comprising a substrate, and an IC chip mounted on the substrate, wherein the module further comprises a protective member bonded to the substrate to cover the IC chip, and a reinforcing member which is harder than the protective member for reinforcing the protective member around the IC chip.
Preferably, the protective member may be formed of a synthetic resin, and the reinforcing member may be formed of a metal or a ceramic material.
Preferably, the protective cap may be formed by molding a resin, and the reinforcing member may be embedded in the protective member by insert molding.
Preferably, the protective member may be provided with a recess for housing the IC chip, and the reinforcing member may include a ring-like member or a ring-like portion fitted in the recess to surround the IC chip.
Preferably, the IC-card module may further comprise an antenna coil formed of a metal wire electrically connected to the IC chip, the antenna coil having a plurality of winding bundles of the metal wire having different winding diameters, wherein a diametrically smaller one of the winding bundles is disposed adjacent the IC chip to surround the IC chip for serving as the reinforcing member.
Preferably, the IC chip and the antenna coil may be packaged in a common resin package.
In accordance with a fifth aspect of the present invention, an IC-card is provided which comprises an IC-card module which includes a substrate, an IC chip mounted on the substrate, a protective member bonded to the substrate to cover the IC chip, and a reinforcing member which is harder than the protective member for reinforcing the protective member around the IC chip; wherein the card member incorporates an IC-card module.
Various features and advantages of the present invention will become clearer from the description given below with reference to the accompanying drawings.